Abstract

Two new stability indicating UV-Spectrophotometric methods have been described for the simultaneous assay of Losartan Potassium and Hydrochlorothiazide in bulk drug and in tablet dosage forms using 0.01 N HCl as the solvent. Method A is based on simultaneous equation or Vierodt’s method and Method B is Q-analysis or Q-absorbance ratio method. The lmax values for Losartan Potassium and Hydrochlorothiazide in the solvent medium were found to be 227.4 nm, 270.4 nm and 256.4 nm, 270.4 nm for Method A and Method B respectively. The systems obey Beer’s law in the range of 2.02-22.22 mg mL-1, 3.03-27.27 mg mL-1 and 5.05-50.50 mg mL-1, 3.03-27.27 mg mL-1 for Losartan Potassium and Hydrochlorothiazide for Method A and Method B respectively. Repeatability, Intra-day and interday precision were found to be 0.202 and 0.670, 0.566-1.31, 0.608- 1.35 for Method A and 0.989 and 0.586, 0.561-1.30, 0.602- 1.33 for Method B. No interference was observed from common tablet adjuvants. t –test and F-test have been applied for the recovery studies of the two methods. The methods were successfully applied to the assay of Losartan Potassium and Hydrochlorothiazide in tablet formulations